Vaporizers are devices are used to vaporize an oil or other vaporizable material into a “vapor” for oral delivery to a user via inhalation. A vaporizer may include several elements, such as a power source, a reservoir containing the oil, and an atomizer to vaporize the oil. Vaporizers with an integrated atomizer and reservoir are referred to as a cartomizer. A vaporizer cartridge contains an integrated atomizer, reservoir and battery attachment assembly such that a power source such as a battery may be easily coupled to the battery attachment assembly to provide power to the vaporizer cartridge. The power source may be a battery attachment assembly attached to a battery. The vaporizer cartridge may include a reservoir for holding the oil and a heating coil with wick for vaporizing the oil to produce a vapor. The oil in the vaporizer cartridge may be consumed when the vaporizer generates a vapor in response to an adult user applying negative pressure to a mouthpiece of the vaporizer (e.g., an inhalation) which causes oil to be drawn to the wick.
All wicks have the disadvantage that they tend to leak and clog. Many vaporizers use a wick made of fiberglass with a nickel cadmium coil. Fiberglass wicks have the disadvantage that they easily clog if the oil has a high viscosity. Fiberglass wicks with nickel cadmium coils also have the disadvantage that they negatively impact the taste of the oil.
There has been a trend towards using ceramic wicks to address some of the disadvantages of fiberglass wicks. However, ceramic wicks have the disadvantage that they do not work well with high viscosity oil or oil of varying degrees of viscosity. Ceramic wicks work within a tight range of viscosity. Consequently, a particular ceramic wick would work only with an oil of a certain viscosity. If an oil of a different viscosity was desired, the user would have to use a different ceramic wick. The ceramic wick is porous, and oil will eventually flow down from the reservoir into the wick. One challenge is to make the oil flow down only when desired.
In order to prevent clogging the vaporizer, oils are treated with thinning agents to lower the viscosity as much as possible for fiberglass wicks, and significantly to whatever range is appropriate for the ceramic wick used. The most common thinning agents are vegetable glycerin (“VG”, a sugar derived from plant oils), propylene glycol (“PG”, a petroleum-based liquid) and polyethylene glycol (“PEG”, a polymer of ethylene oxide). VG and PG are primarily used in the context of e-cigarettes, and PG and PEG are primarily used in the context of cannabis oils. Research shows that these substances may not be safe to use when they are inhaled as a vapor. When heated to temperatures that are commonly reached by vaporizers, VG, PG and PEG produce aerosols that contain carbonyls such as formaldehyde, acetaldehyde, and acrolein. The production and inhalation of compounds produced by heated thinning agents is problematic, as these compounds pose potential health risks. The International Agency for Research of Cancer (IARC) classifies formaldehyde as a Group 1 Agent, which is a compound that is known to be carcinogenic. The IARC classifies acetaldehyde as a Group 2B Agent, which is possibly carcinogenic to humans34 and similar to formaldehyde. Acrolein causes DNA damage and inhibits DNA repair, which suggests that it is a major determinant of lung cancer and lung carcinogenesis. (See, Carbonyl Compounds Produced by Vaporizing Cannabis Oil Thinning Agents, Troutt William D. and DiDonato Matthew D. The Journal of Alternative and Complementary Medicine. March 2017).
Thinning agents have the additional disadvantage in that they compromise the taste of the oil. Aside from the general negative impact on taste from the thinning agents, viscosity itself also impacts the taste of the oil. Generally speaking, higher viscosity oils tend to taste better than lower viscosity oils.
Even with the use of thinning agents, vaporizers tend to clog in response to variations in temperature and pressure. Such variations tend to push oil out of the reservoir into the wick. For example, when left in the car on a hot day, pressure in a closed container such as the vaporizer cartridge will build up, forcing the oil out of the reservoir and into the wick. Additionally, temperature will change the viscosity of the oil. In the case of a ceramic wick, any change of viscosity outside its range will affect its ability to vaporize the oil, and will potentially lead to clogging.
The addition of terpenes also affect the viscosity of oil. Terpenes have very low viscosity, and when added back into the extracted oil, changes the viscosity of oil. Unadulterated oil with have a viscosity of between 150 k cps to 300 k cps has a honey-like consistency. Adding a thinning agent such as PEG will bring the viscosity down to approximately 20 k cps, which would be required to work with a fiberglass wick. The viscosity of pre-extract terpenes is between 2 k-5 k cps. The pre-extract terpenes can be added to the oil to bring the overall viscosity down. The cartridge of the present invention can be used with oil with a viscosity between 15 k-50 k cps.
Attempts to use oils without thinning agents have resulted in high costs, problems and high return rates. Other attempts to address these problems are high end vertical wicks. One such solution has a vertical ceramic wick in a stainless steel housing and a glass tank. These have the disadvantage that they are very expensive, costing about 500% more than a ceramic wick.
There is a need for a vaporizer that works well with high viscosity oil or oils with different viscosity levels, does not require thinning agents, does not clog, and can be manufactured at a reasonable cost. Such a vaporizer allows use of 100% pure oil with no harmful additives, such as PG, VG or PEG. The present invention overcomes these limitations and provides other related advantages.